The present invention relates to wheeled vehicles such as a motorcycle provided with a front master cylinder and a rear master cylinder capable of separately actuating a front wheel brake and a rear wheel brake, and more specifically, to an anti-lock brake device which can efficiently brake the front and rear wheels without locking of these wheels under braking operation.
Some of the present inventors have already proposed a brake device of the type as described in U.S. Pat. No. 4,315,659 in which an operating portion of the wheel brake is provided with a control oil pressure chamber which may apply back pressure to the operating portion to decrease the braking torque generated in the wheel brake, and the control oil pressure chamber is selectively placed in communication with an oil tank and an oil pressure source through control valves.